In magnetic recording devices, magneto-resistive heads are commonly used for reading signals encoded on a recording media. The recording media may take a number of forms including a disk or a tape. The signals are often in digital format. The digital information is stored on the recording media as a sequence of magnetic flux changes. One flux direction is designated as a logic one and the other flux direction is designated as a logic zero. When the signal is being read back off of the recoding media by the magneto-resistive head, the read head generates a positive voltage pulse for one flux direction and a negative voltage pulse for the other flux direction. Unfortunately, the amplitude of the pulses may not be identical. This is known as asymmetry in the read head. The amount of asymmetry may vary from head to head. The asymmetry can result in unwanted read errors.